I should think so

I should think so

I would naturally expect that this would happen or be true. A: "My manager said you can get a refund on the item." B: "I should think so—it arrived broken in two pieces!"
See also: should, think
Farlex Dictionary of Idioms.

I should think ˈso/ˈnot

(also I should think she, etc. ˈis/ˈdoes/ˈdid, etc.) used for emphasis when agreeing that something is right or correct: ‘He didn’t give the waiter a tip.’ ‘I should think not, after such bad service.’ ‘He finally apologized for what he said.’ ‘I should think so.’ ‘I’m very angry with my son.’ ‘I should think you are. He’s behaved very badly indeed.’
See also: not, should, think
Farlex Partner Idioms Dictionary
See also:
  • I should hope so
  • I would hope so
  • I should think not
  • I should think so/not
  • I would hope not
  • I should hope so/not
  • I should hope not
  • do what comes naturally
  • natch
  • cut out for (someone or something)